This challenge is about ECDSA nonce-reuse weakness. See [this post](https://ropnroll.co.uk/2017/05/breaking-ecdsa/) for explanation.

Solver code: [ecdsa_solve.py](https://github.com/CTF-STeam/ctf-writeups/blob/master/2021/TenableCTF/ecdsa_solve.py)

Flag: `flag{cRypt0_c4r3fully}`

Original writeup (https://github.com/CTF-STeam/ctf-writeups/tree/master/2021/TenableCTF#ecdsa-implementation-crypto---225-pts).